# ========================================
# Multi-stage Dockerfile for Backend Node.js
# ========================================

# ========================================
# Stage 1: Base
# ========================================
FROM node:20-alpine AS base

# Install dumb-init for proper signal handling
RUN apk add --no-cache dumb-init

# Set working directory
WORKDIR /app

# Copy package files for dependency installation
COPY package*.json ./

# ========================================
# Stage 2: Dependencies
# ========================================
FROM base AS dependencies

# Install ALL dependencies (including devDependencies for build)
RUN npm install

# ========================================
# Stage 3: Development
# ========================================
FROM dependencies AS development

# Set NODE_ENV
ENV NODE_ENV=development

# Copy application code
COPY . .

# Expose port
EXPOSE 3000

# Use dumb-init to handle signals properly
ENTRYPOINT ["dumb-init", "--"]

# Start with nodemon for hot reload
CMD ["npm", "start"]

# ========================================
# Stage 4: Production Dependencies
# ========================================
FROM base AS production-dependencies

# Install only production dependencies
RUN npm install --only=production && \
    npm cache clean --force

# ========================================
# Stage 5: Production Build
# ========================================
FROM base AS production

# Set NODE_ENV
ENV NODE_ENV=production

# Copy production dependencies
COPY --from=production-dependencies /app/node_modules ./node_modules

# Copy application code
COPY . .

# Create non-root user for security
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001 && \
    chown -R nodejs:nodejs /app

# Switch to non-root user
USER nodejs

# Expose port
EXPOSE 3000

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
    CMD node -e "require('http').get('http://localhost:3000/health', (r) => {process.exit(r.statusCode === 200 ? 0 : 1)})"

# Use dumb-init to handle signals properly
ENTRYPOINT ["dumb-init", "--"]

# Start the application
CMD ["node", "server.js"]